Ok so this annoying. I’m getting excess extrusion from both PLA and ABS. It just flows out before, during and after prints. Never seen ABS do that. I’m assuming its a temperature issue but what would you all guess is the problem? 3mm filament through a Bukobot Duo. I’ve had the Deezmaker folks look at this with no luck on finding a solution. The issue is most noticeable on layer one and whenever the head lifts. Even when I try to force thin the print by exaggerating the filament diameter, it doesn’t work. Help?
Edit: Lowering temps just made prints worse. The first picture shows me changing z height in case of compression and upping the filament diameter to forcibly thin the plastic. Same results throughout with bad adhesion by the last cube since it printed rather lifted from the platform.
I’ve never had filament not drip while the nozzle was heated. I use a MBI Replicator 2X at work with ABS and it “drools” while heating and cooling. The only time it doesn’t is during printing because the g-code retracts when appropriate. The same can be said for my printer at home where I print PLA. If there is filament in the hot zone of your nozzle, and the nozzle is heated, I don’t think it’s abnormal for filament to slowly drip out.
Yea I agree with you that its normal for some oozing, but nothing like in the second photo where you can see the excess pulling as the extruder left the model. Just note that I’ve looked into my head being too low (usual curprit to ugly first layers) but I’m kosher there. The first photo shows my attempts to remedy the issue through diameter & multiplier. The last one is so lifted it didn’t get any good adhesion. All my corners look ugly from flowing out during lifting on the z.
Did the deezmaker folk check your thermistor? If it’s loose or faulty you may be extruding too hot due to an incorrect reading. Try dialling the temp down until the extrudiate stops flowing smoothly then bump up the temp by 5-10 degrees.
What slicer are you using? Do both slic3r and kisslicer I believe default the first layer to over extrude to account for uneven beds.
I’m not quite sure I understand what you mean by the head lifting. Generally the z only moves while still on a layer during retract. Between layers the head lifts, then let’s back one it’s ready to extrude. This can be stopped in slicer settings though where you set the retract.
I think the prints look fine in the corners, I must not be sewing what you’re describing. As for stringing when the head moves away, both printers i use do that. You can up your retract and prime to minimize this, but again, I don’t seem to be seeing the problem :o/
Oh, and on the second picture, you are clearly showing signs of over-extrusion - the nozzle is snow-plowing ridges through the excess plastic. Try raising your nozzle if it’s only happening on the first layer, or adjust your filament diameter in the slicer as needed.
@Tim_Rastall I’ll give that a try, lets see how low I can get it before it stops up. @Joseph_Chiu It’s not my Z height, we get bad adhesion and it still plows through. Filament diameter was exaggerated a by .5 and still no changes. It’s gotta be a false reading of temperatures or I’m stumped! @Dante_Ranieri I think its circular but I’ll confirm that soon.
G’ah. My original comment seemed to have disappeared – to recap that one really quickly, A) make sure you don’t have any residue of other filament from before – purge by running your extruder hot for a while (say 30 seconds) before lowering the temp to match the loaded filament – and try lowering your temperature in 10 degree steps, and then fine tune in 5 degree steps until you are just hot enough to extrude at a decent rate.
As for the bad adhesion – just to be sure – did you wipe it down with acetone? Also, have you tried blue painter’s tape?
And, finally, try going slower. Sometimes, that makes all the difference.
Thanks @Joseph_Chiu I’ve used acetone and blue painters tape when needed. I’m still figuring this new bot out, but my buko mini gets the full treatment. I have run new plastic through the Duo though for a while now so I don’t suspect that is the problem.
My tip when it comes to adhesion is not to run it too hot and if you are getting decent adhesion with PLA with just painters tape, then let your HBP go from 0 to 60~ for bigger prints. It won’t distort the model but apply enough heat to stay on the platform for more than 4-6 hours & not show strain on the lowest layers. Some of my bad curls for ABS also came from my HBP temp being too high.
@Tim_Rastall Ok so I got extrusion @ 205 ABS with one slip from the motor but I still see the issue. Lowering the temps by 20 definitely made the print worse but the “plowing” is still occurring from excess extrusion. http://www.imgur.com/Qz9JcjL.jpeg
Now, I forgot to mention, my first picture on this post is a mix of raising the z endstop and exaggerating my filament diameter/multiplier on a 20mm box. My usual go-to fixes, ze aren’t working!? lol
At some point, it should. Try adjusting by about 10-15%. Also, some slicers have settings to over-extrude on the first layer – so make sure that’s not the case here.
